The present invention relates to television broadcasting systems, and more particularly, to a circuit and method for performing a specific function at a receiving side by use of a code transmitted from a transmitting side when a video signal, in which the code for controlling the specific function of the receiving side is inserted, is transmitted.
Generally, a television or video tape recorder (VTR) has a timer function. I have observed however that this function may not be reliably used for example, in an area in which frequent power failures occur. It is also a problem if a user either thinks that it is simply too much trouble to adjust the time or does not know the routine required by an appliance for adjusting the time. Moreover, in preparation of a power failure, a battery may be used as the backup source of electric power. If the user forgets to replace the battery however, a timer needs to be manually adjusted. If the timer function does not work, then a scheduled recording of a program also will not operate. Therefore, it is very important in some cases, to adjust the timer to the correct time. Although such convenient functions as the pre-set turn-on of appliances such as televisions and video tape recorders have been provided as built-in functions, in a television or in a video recording machine, it is my conclusion that it is unfortunate that these convenient functions can not be reliably used due to problems in keeping the on-board time maintained by the appliance correctly adjusted.
Typically, a broadcast station notifies a viewer of specific programs prior to the normally scheduled broadcast of the programs. If it is desired to reserve the recording of a program, the viewer needs to press multiple keys on a keyboard of the VTR or a remote controller. By way of example, in the Video Cassette Recorder Programming Via Teletext Transmissions described by U.S. Pat. No. 4,908,707 to John R. Kinghorn, the reservation of recording a broadcast is accomplished by selecting a desired program by use of a cursor from among the contents of a schedule received as a teletext transmission that is displayed on teletext pages of the television screen. It seems to me that this method is inconvenient because the user has to press several keys repeatedly, i.e., the user must select a teletext page corresponding to a source, a cursor key must be pressed several times to obtain alignment with the desired program, and a record that key must be pressed to store the necessary information in a memory of the video recorder.
In the System And Process For VCR Scheduling mentioned in U.S. Pat. No. 4,977,455 to Patrick Young, a cue, i.e., an audio sound or a visual symbol or message generated by a microprocessor in response to a broadcast indicating the availability of supplemental information relating to the broadcast received at a teletext receiver, is displayed on the television screen. The user must however, operate a store key on the remote control in near synchronism with the cue to store schedule information and to thereby program the appliance to automatically record the supplemental information when it is broadcast.
The TV Schedule System And Process embodiment shown in U.S. Pat. No. 4,706,121 to Patrick Young schedule information is transmitted either in the vertical or horizontal blanking interval or as a separate broadcast, such as a frequency modulation (FM) broadcast. Menus are displayed on the television screen and the user, by accurately manipulating a plurality of keys on a keyboard of a remote control in the correct sequence, for example, may select desired information to be stored so as to automatically control a television tuner or a video recorder to record certain programs. The stored information is automatically updated (without user interaction) in case of a schedule change regarding when the program is actually broadcast. Error checking and/or correction is performed on each block of data transmitted.
A more recent effort is represented by the Automatic Tuning Radio/TV Using Filtered Seek described in U.S. Pat. No. 5,210,611 to Yee et al., where a tuner is controlled according to digital information transmitted in either the vertical blanking interval of the television signal or in an FM subcarrier on an audio signal, while in the Video Signal Processor of U.S. Pat. No. 5,063,456 to Horiuchi et al. endeavors to eliminate data in the vertical blanking interval in order to insert time codes therein, in an effort to provide an accurate time code reading in a video tape recorder fitted with a circuit for recording or reproducing time code signals. However, the time codes are not directed towards real time but are instead for designating tape locations (addresses). Accordingly, the time codes in Horiuchi et al. can not be used to adjust the timing circuit of a VTR according to real time.